When Henry's father goes missing in the forest on her tenth birthday, her entire world shatters. The last thing she expects is for him to emerge from the trees exactly one year later, unharmed and bearing a gift for her--a strange necklace.

Everyone says her father's reappearance is a miracle, but Henry wants real answers to her questions. Where did her father go? How did he get back? And what's the truth behind his gift?

Wearing the necklace and carrying only a simple map, Henry enters the same forest that swallowed her father. But beyond the trees, she finds a world more incredible and dangerous than she ever imagined. It's a place for all who are lost, and there's no clear method of escape. As Henry follows in her father's footsteps and searches for a way home, she discovers that the truth she's seeking isn't as simple as she hoped, and if she wants to leave this world, she'll have to be braver than she's ever been.